Fabrication of p-type 2D single-crystalline transistor arrays with Fermi-level-tuned van der Waals semimetal electrodes

• Published in: Nature communications Vol. 14; no. 1; p. 4747
• Main Authors: Song, Seunguk, Yoon, Aram, Jang, Sora, Lynch, Jason, Yang, Jihoon, Han, Juwon, Choe, Myeonggi, Jin, Young Ho, Chen, Cindy Yueli, Cheon, Yeryun, Kwak, Jinsung, Jeong, Changwook, Cheong, Hyeonsik, Jariwala, Deep, Lee, Zonghoon, Kwon, Soon-Yong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.08.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 132/122; 140/133; 140/146; 142/126; 147/135; 147/137; 147/28; 147/3; 639/301/357/1018; 639/925/927/1007; Arrays; Contact resistance; Electrodes; Fabrication; Gold; Grain growth; Humanities and Social Sciences; Low temperature; Metallizing; Metalloids; Molybdenum compounds; multidisciplinary; Nanoelectronics; P-type semiconductors; Science; Science (multidisciplinary); Semiconductors; Single crystals; Tellurides; Transistors; Work functions
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-40448-x

High-performance p -type two-dimensional (2D) transistors are fundamental for 2D nanoelectronics. However, the lack of a reliable method for creating high-quality, large-scale p -type 2D semiconductors and a suitable metallization process represents important challenges that need to be addressed for future developments of the field. Here, we report the fabrication of scalable p -type 2D single-crystalline 2H-MoTe 2 transistor arrays with Fermi-level-tuned 1T’-phase semimetal contact electrodes. By transforming polycrystalline 1T’-MoTe 2 to 2H polymorph via abnormal grain growth, we fabricated 4-inch 2H-MoTe 2 wafers with ultra-large single-crystalline domains and spatially-controlled single-crystalline arrays at a low temperature (~500 °C). Furthermore, we demonstrate on-chip transistors by lithographic patterning and layer-by-layer integration of 1T’ semimetals and 2H semiconductors. Work function modulation of 1T’-MoTe 2 electrodes was achieved by depositing 3D metal (Au) pads, resulting in minimal contact resistance (~0.7 kΩ·μm) and near-zero Schottky barrier height (~14 meV) of the junction interface, and leading to high on-state current (~7.8 μA/μm) and on/off current ratio (~10 5 ) in the 2H-MoTe 2 transistors. The fabrication of high-performance p -type 2D transistors is still challenging. Here, the authors report the realization of wafer-scale p -type 2H-MoTe 2 transistor arrays contacted by Fermi-level tuned semimetallic 1T’-MoTe 2 electrodes, leading to improved contact resistance and device performance.